Fix preview label to properly create pre-release NuGet packages

The root cause was that anothrNick/github-tag-action ignores the PRERELEASE
environment variable when running on the default branch (main), always creating
production releases instead of preview releases.

This fix:
- Conditionally uses the existing action only for release labels
- Manually creates preview tags with -preview suffix when preview label is present
- Maintains existing norelease functionality
- Properly sets all environment variables and outputs

Co-authored-by: matt-goldman <[email protected]>

Author: Copilot

.github/workflows/ci.yml

@@ -63,19 +63,61 @@ jobs:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
 
-      - name: GitHub Tag Bump
-        id: tag_bump
-        if: env.NORELEASE != 'true'
+      - name: GitHub Tag Bump (Release)
+        id: tag_bump_release
+        if: env.PRERELEASE == 'false' && env.NORELEASE != 'true'
         uses: anothrNick/[email protected]
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           INITIAL_VERSION: 1.0.0
           DEFAULT_BUMP: ${{ env.BUMP }}
-          PRERELEASE: ${{ env.PRERELEASE }}
-          PRERELEASE_SUFFIX: 'preview'
+          PRERELEASE: false
+
+      - name: Get Latest Tag
+        id: get_latest_tag
+        if: env.PRERELEASE == 'true' && env.NORELEASE != 'true'
+        run: |
+          LATEST_TAG=$(git describe --tags --abbrev=0 2>/dev/null || echo "1.0.0")
+          echo "latest_tag=$LATEST_TAG" >> $GITHUB_OUTPUT
+
+      - name: Calculate Preview Version
+        id: calc_preview_version
+        if: env.PRERELEASE == 'true' && env.NORELEASE != 'true'
+        run: |
+          LATEST_TAG="${{ steps.get_latest_tag.outputs.latest_tag }}"
+          # Remove 'v' prefix if present
+          LATEST_TAG=${LATEST_TAG#v}
+          
+          # Split version into parts
+          IFS='.' read -r MAJOR MINOR PATCH <<< "$LATEST_TAG"
+          
+          # Bump version based on BUMP type
+          if [[ "${{ env.BUMP }}" == "major" ]]; then
+            MAJOR=$((MAJOR + 1))
+            MINOR=0
+            PATCH=0
+          elif [[ "${{ env.BUMP }}" == "minor" ]]; then
+            MINOR=$((MINOR + 1))
+            PATCH=0
+          else
+            PATCH=$((PATCH + 1))
+          fi
+          
+          # Create preview version
+          NEW_VERSION="${MAJOR}.${MINOR}.${PATCH}-preview"
+          echo "new_version=$NEW_VERSION" >> $GITHUB_OUTPUT
+
+      - name: Create Preview Tag
+        id: tag_bump_preview
+        if: env.PRERELEASE == 'true' && env.NORELEASE != 'true'
+        run: |
+          NEW_VERSION="${{ steps.calc_preview_version.outputs.new_version }}"
+          git tag "$NEW_VERSION"
+          git push origin "$NEW_VERSION"
+          echo "new_tag=$NEW_VERSION" >> $GITHUB_OUTPUT
 
     outputs:
-      new_version: ${{ steps.tag_bump.outputs.new_tag }}
+      new_version: ${{ env.NORELEASE != 'true' && (steps.tag_bump_release.outputs.new_tag || steps.tag_bump_preview.outputs.new_tag) || '' }}
       norelease: ${{ env.NORELEASE }}